This project proposes to conduct a 5 year study of the effectiveness of an early intervention program for kindergarten-aged children who are both socially aggressive and have Attention Deficit Hyperactivity Disorder (ADHD). The treatment program will involve a combination of multiple methods of behavioral and cognitive interventions as well as psychopharmacology, as required, to test the effectiveness of this program for altering the educational, social, and familial negative outcomes of these children. Past research clearly indicates that aggressive ADHD children are at high risk for later academic failure, grade retention, school suspension and expulsion, as well as later substance abuse and antisocial activity. This study combines eight of the most effective interventions for aggressive ADHD children into an intensive intervention program that is integrated with the children's full-day kindergarten program through the Worcester Public Schools. A total of 80 aggressive ADHD children and 40 normal children will be recruited into the project over a 2 year period (as two cohorts of 60 children each) form the routine kindergarten screening conducted each fall in the public schools. All children will receive an extensive initial assessment including measures of intelligence and academic achievement as well as of adaptive behavior, memory, motor abilities, attention, impulsivity, behavior and social conduct, medical and developmental history, psychiatric symptoms, and direct behavioral observations of school conduct. Half of the aggressive ADHD children will then be assigned to the multi-method intervention for their kindergarten year and half to the regular kindergarten program on a random basis. These two groups as well as the normal control group will be followed and re-evaluated at the end of their kindergarten year as well as at the end of first and second grade, providing a two year post-treatment follow-up. The results will provide important information on the nature of ADHD in preschool age children, its developmental course in the untreated ADHD group, and the effectiveness of the early multi-method intervention program in reducing the risk for later negative outcomes. Specifically, the program of treatment is intended to reduce the need for later special educational and psychiatric interventions as well as improve the academic performance and adjustment of these high-risk children.